Rockstar has yet to officially announce a release date for the PC, PS4 and Xbox one versions of the game but there is evidence that a PC version at least is in the works with reference to a "GTA5.exe" file in the latest AMD Catalyst driver. Rockstar has officially stated there are no plans for PS4 and Xbox One versions of the game, but PS4 source code has been found in the Xbox 360 version of the game and it is surely inevitable that next-gen version will arrive sometime next year. More info can be found below: